[Evaluation of retention behavior of carbohydrate compounds on the zwitterionic hydrophilic interaction liquid chromatographic column].

Because of the strong polarity of carbohydrate compounds which have weak retention in reverse-phase liquid chromatography (RPLC) , hydrophilic interaction liquid chromatography (HILIC) is suitable for the separation and analysis of the carbohydrate compounds. In this study, nine carbohydrate compounds were selected as the test probes to systematically evaluate the retention behavior of the carbohydrate compounds on a Click TE-Cys column with zwitterionic stationary phase. And the effects of the ratio of organic phase and salt concentration in mobile phase on the retention behavior were investigated as well.

Chromatographic evaluation and application of silica based azide-modified stationary phase under hydrophilic interaction liquid Chromatography mode.

Hydrophilic interaction liquid chromatography (HILIC) has attracted more and more interests in recent years. However, the stationary phases for HILIC are still scarce. More stationary phases and separation methods should be developed.

Separation and characterization of bufadienolides in toad skin using two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography coupled with mass spectrometry.

Bufadienolides possess various bioactivities especially antitumor. Due to the high structural diversity, the separation of bufadienolides often suffers from coelution problem on conventional RP columns. In this work, an off-line two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography (2D-NPLC×RPLC) method was developed to separate and characterize bufadienolides in toad skin.

Hydroxycinnamic acid amides from Scopolia tangutica inhibit the activity of M1 muscarinic acetylcholine receptor in vitro.

Scopolia tangutica Maxim (S. tangutica) extracts have been traditionally used as antispasmodic, sedative, and analgesic agents in Tibet and in the Qinghai province of China. Their active compositions are however poorly understood.

Disaccharide-driven transition of macroscopic properties: from molecular recognition to glycopeptide enrichment.

We reported a three-component smart polymer, which could discriminate disaccharide homologues and translate the recognition signals into distinct differences in the macroscopic properties (i.e. wettability and adhesion force) of materials.

Improvement of chiral stationary phases based on cinchona alkaloids bonded to crown ethers by chiral modification.

To improve the chiral recognition capability of a cinchona alkaloid crown ether chiral stationary phase, the crown ether moiety was modified by the chiral group of (1S, 2S)-2-aminocyclohexyl phenylcarbamate. Both quinine and quinidine-based stationary phases were evaluated by chiral acids, chiral primary amines and amino acids. The quinine/quinidine and crown ether provided ion-exchange sites and complex interaction site for carboxyl group and primary amine group in amino acids, respectively, which were necessary for the chiral discrimination of amino acid enantiomers.

A controlled thiol-initiated surface polymerization strategy for the preparation of hydrophilic polymer stationary phases.

A controlled thiol-initiated surface polymerization strategy has been successfully developed and employed to prepare hydrophilic polymer stationary phases, which exhibited excellent chromatographic performance and protein non-fouling properties.

Sequential enrichment of singly- and multiply-phosphorylated peptides with zwitterionic hydrophilic interaction chromatography material.

An interesting and novel method for the selective and sequential enrichment of singly- and multiply-phosphorylated peptides with a zwitterionic material "Click TE-Cys" is presented. Retention mechanisms between phosphopeptides and Click TE-Cys are systematically investigated by checking the influence of acetonitrile content, pH value, and buffer concentration on the retention of phosphopeptides. Both hydrophilic interaction and electrostatic interaction are involved in retention between phosphopeptides and Click TE-Cys.

Protection of seven dibenzocyclooctadiene lignans from Schisandra chinensis against serum and glucose deprivation injury in SH-SY5Y cells.

Dibenzocyclooctadiene lignans, the major active components of fruit of Schisandra chinensis (Turcz.) Baill., have been found to have activities that could prevent prostate and thyroid cancer, hepatotoxicity, oxidative stress-induced cerebral injury, etc.

A polyvinyl alcohol-coated silica gel stationary phase for hydrophilic interaction chromatography.

Multiple layers of polyvinyl alcohol (PVA) coating are generated onto silica gel by thermal immobilization to form a stationary phase applied for hydrophilic interaction liquid chromatography (HILIC). It offers an easy way to manipulate the thickness of PVA coating and the obtained stationary phase demonstrated high efficiency and high chemical stability.

A polyvinyl alcohol-functionalized sorbent for extraction and determination of aminoglycoside antibiotics in honey.

A novel highly hydrophilic sorbent simply prepared by coating polyvinyl alcohol (PVA) onto silica gel was used for extraction and determination of aminoglycoside antibiotics (AAs). The fabricated PVA coating is aimed to effectively protect core silica gel inside and offers good hydrophilic property. In combination of hydrophilic interaction chromatography tandem mass spectrometry, the performance of the sorbent was evaluated by selecting four model AAs (dihydrostreptomycin, streptomycin, kanamycin, spectinomycin).

Hydrophilic interaction liquid chromatography for the separation, purification, and quantification of raffinose family oligosaccharides from Lycopus lucidus Turcz.

A systematic strategy based on hydrophilic interaction liquid chromatography was developed for the separation, purification and quantification of raffinose family oligosaccharides from Lycopus lucidus Turcz. Methods with enough hydrophilicity and selectivity were utilized to resolve the problems encountered in the separation of oligosaccharides such as low retention, low resolution and poor solubility. The raffinose family oligosaccharides in L.

Evaluation of separation properties of a modified strong cation exchange material named MEX and its application in 2D-MEX × C18 system to separate peptides from scorpion venom.

Peptides from scorpion venom represent one of the most promising drug sources for drug discovery for some specific diseases. Current challenges in their separation include high complexity, high homologies and the huge range of peptides. In this paper, a modified strong cation exchange material, named MEX, was utilised for the two-dimensional separation of peptides from complex scorpion venom.

Comparison of three magnetic-bead-based RNA extraction methods for detection of cucumber green mottle mosaic virus by real-time RT-PCR.

To determine the efficiency of RNA extraction methods based on magnetic beads, three different bead-based methods (one using silica-coated magnetic beads [SMNP], one using immunomagnetic beads conjugated to a specific antibody [IMB], and one using magnetic beads to nonspecifically adsorb virions [MNP]) were compared with the TRIzol method for the extraction of cucumber green mottle mosaic virus (CGMMV) RNA from cucumber leaves by real-time RT-PCR. The results indicated that the extraction efficiency of the SMNP method was 10 times higher than those of the IMB and MNP methods and 100 times higher than that of the TRIzol method. Therefore, the SMNP method could be considered for use in quarantine measures for the prevention and control of the disease caused by CGMMV.

An arginine-functionalized stationary phase for hydrophilic interaction liquid chromatography.

An arginine-functionalized stationary phase for hydrophilic interaction liquid chromatography (HILIC) has been prepared for the first time by clicking arginine onto silica gel. It offers an efficient separation of organic acids, nucleotides and sugars. More interestingly, it exhibited excellent selectivity and enrichment toward acidic glycopeptides, even at a ratio of 1 : 150 to non-glycopeptides.

Hydrophilic-subtraction model for the characterization and comparison of hydrophilic interaction liquid chromatography columns.

Nowadays more and more hydrophilic interaction liquid chromatography (HILIC) columns with diverse functional groups have become commercially available, which pose a challenge to select an appropriate one. However, there is no universal model to provide guidance for selecting HILIC columns. To handle this problem, a retention model named "hydrophilic-subtraction model" was developed to characterize and compare HILIC columns.

[Structural characterization of Astragalus polysaccharides using partial acid hydrolysis-hydrophilic interaction liquid chromatography-mass spectrometry].

Water-soluble polysaccharides from traditional Chinese medicine (TCM) have properties of broad-spectrum treatment and low toxicity, making them as important components in natural medicines and health products. In order to solve the problem of polysaccharides characterization caused by their complex structures, a "bottom-up" approach was developed to complete the characterization of polysaccharides from Astragalus. Firstly, Astragalus pieces were extracted with hot water and then were precipitated by ethanol to obtain Astragalus polysaccharides.

The influence of organic sample solvents on the separation efficiency of basic compounds under strong cation exchange mode.

This study investigated the influence of organic sample solvents on separation efficiency of basic compounds under strong cation exchange (SCX) mode. The mixtures of acidic aqueous solution and organic solvent such as acetonitrile, ethanol, methanol and dimethyl sulfoxide (DMSO) were tested as sample solvents. For later-eluting analytes, the increase of sample solvent elution strength was responsible for the decrease of separation efficiency.

Qualitative and quantitative analysis of an alkaloid fraction from Piper longum L. using ultra-high performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry.

In a previous research, an alkaloid fraction and 18 alkaloid compounds were prepared from Piper longum L. by series of purification process. In this paper, a qualitative and quantitative analysis method using ultra-high performance liquid chromatography-diode array detector-mass spectrometry (UHPLC-DAD-MS) was developed to evaluate the alkaloid fraction.

Preparation and chromatographic evaluation of a newly designed steviol glycoside modified-silica stationary phase in hydrophilic interaction liquid chromatography and reversed phase liquid chromatography.

A diterpene glycoside compound, rebaudioside A (commonly abbreviated as RA), was immobilized onto porous silica surface through "thiol-ene" click chemistry strategy. The successful immobilization of the RA on the silica support was confirmed by FT-IR and elemental analysis. Chromatographic characteristics of the new stationary phase, named Click TE-RA, were evaluated by a set of diverse analytes such as carbohydrates, nucleosides, and organic acids in hydrophilic interaction liquid chromatography (HILIC) mode.

Evaluation of a silicon oxynitride hydrophilic interaction liquid chromatography column in saccharide and glycoside separations.

The retention characteristics of a silicon oxynitride stationary phase for carbohydrate separation were studied in hydrophilic interaction chromatography mode. Four saccharides including mono-, di-, and trisaccharides were employed to investigate the effects of water content and buffer concentration in the mobile phase on hydrophilic interaction liquid chromatography retention. For the tested saccharides, the silicon oxynitride column demonstrated excellent performance in terms of separation efficiency, hydrophilicity, and interesting separation selectivity for carbohydrates compared to the bare silica stationary phase.

High-performance liquid chromatography separation of cis-trans anthocyanin isomers from wild Lycium ruthenicum Murr. employing a mixed-mode reversed-phase/strong anion-exchange stationary phase.

The cis-trans isomerism is a common phenomenon for acylated anthocyanins. Nevertheless, few studies reported effective methods for the preparation of isomeric anthocyanins from natural products. In this work, a high-performance liquid chromatography (HPLC) method was developed to efficiently purify anthocyanin isomers from Lycium ruthenicum Murr.

Preparation and evaluation of novel chiral stationary phases based on quinine derivatives comprising crown ether moieties.

The C9-position of quinine was modified by meta- or para-substituted benzo-18-crown-6, and immobilized on 3-mercaptopropyl-modified silica gel through the radical thiol-ene addition reaction. These two chiral stationary phases were evaluated by chiral acids, amino acids, and chiral primary amines. The crown ether moiety on the quinine anion exchanger provided a ligand-exchange site for primary amino groups, which played an important role in the retention and enantioselectivity for chiral compounds containing primary amine groups.

Heat-shrink tubing as a solid-phase microextraction coating for the enrichment and determination of phthalic acid esters.

Heat-shrink tubing, which shrinks in one plane only (its diameter) when heated, commonly used for sealing protection in electrical engineering, was found to be able to function as a solid-phase microextraction coating. Its utility was demonstrated for the determination of phthalic acid esters in an aqueous solution combined with high-performance liquid chromatography equipped with a UV absorbance detector. The preparation procedure was rather simple and only ∼10 min was needed.

[Preparation of triterpene saponins from Platycodon grandiflorum by two-dimensional hydrophilic interaction liquid chromatography-reversed phase liquid chromatography].

A two-dimensional (2-D) preparative liquid chromatography method was developed for the preparation of triterpene saponins from Platycodon grandiflorum using hydrophilic interaction liquid chromatography (HILIC) coupled with reversed phase liquid chromatography (RPLC). At first, the crude extract was obtained from Platycodon grandiflorum by boiled alcohol precipitation. Then, the concentrated crude extracts were continuously pretreated using solid phase extraction (SPE) under reversed-phase and hydrophilic-phase modes to remove the impurities.